Manager Shaun Derry says Cambridge United are "devastated" by their defeat by League Two strugglers Stevenage.
Boro, under caretaker Darren Sarll, beat Derry's play-off hopefuls 2-0 for their first home win since November.
"We're devastated for the performance that we put in. That's not a Cambridge United performance," said Derry.
"We were never able to play on the front foot. If you look at the goals it was through our faulty play rather than anything Stevenage created."
Derry added to BBC Radio Cambridgeshire: "You always want whatever goal you concede to be earned - I don't think we made Stevenage really, really earn their goals today."
The defeat, which followed victories over Leyton Orient and Dagenham, saw the U's drop to 11th in the League Two table, four points off the final play-off place.
"The good thing for us is that we have shown in the past that we can respond to the difficulties," continued Derry.
"That's what we've got to do again. You're never going to have it all your own way. It's a group that's been in transition, but it wasn't a performance I was proud of."